Navegando por Assunto "Lipopolissacarideos"

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Acesso aberto (Open Access)
Citoproteção do ácido kójico (AK) na morte induzida por LPS em células de Muller de retina de embrião de galinha
(Universidade Federal do Pará, 2017-12-07) CARVALHO, Giselle Cristina Brasil; NASCIMENTO, José Luiz Martins do; http://lattes.cnpq.br/7216249286784978
5-Hydroxy-2-hydroxymethyl-γ-pyrone (AK), a known inhibitor of tyrosinase, an enzyme important for melanin synthesis and therefore used for pigmentation disorders. AK also promotes significant activation of macrophages and promotes cytoplasmic accumulation of reactive oxygen species (ROS), suggesting its role as a potentiator of the immune system and microbicide. There is no work in literature that shows the action of AK in the central nervous system (CNS) as a cellular activator and its possible protective role against infections. To test this hypothesis, it use retinal Muller glia which have similar properties to those of macrophages. Therefore, the present work evaluates the action of AK as a possible protective role in LPS-induced cell death in culture of glial cells from chicken embryos. Cultures enriched with glial cells were treated with AK (10, 25, 50 and 100 μM) and LPS (0.1, 10, 100, and 500 ng / ml) for 24 hours. After treatment, the cells did not show AK-treated cytotoxicity; however, treated with LPS, cell death occurred in a dose-dependent manner. We verified the accumulation of EROs in groups treated with AK (100 μM) and LPS (100 and 500 ng / ml). Cultures co-treated with AK and LPS in the same concentrations there was a reduction of accumulation of EROs. AK was also able to inhibit the activity of antioxidant enzymes, (catalase and Superoxide dismutase) and glutathione levels, while LPS produces an increase in the activity of these antixodants. AK was able to inhibit the antioxidant enzymes and glutathione from the increase induced by LPS. These data show that AK promotes the modulation of oxidative and antioxidative balance as a possible protective mechanism in the cell death produced by LPS in Müller's Glia enriched cells.
Acesso aberto (Open Access)
Efeitos do tratamento agudo sistêmico de beta-cariofileno em camundongos fêmea saudáveis e em modelo de inflamação sistêmica
(Universidade Federal do Pará, 2021-07) MONTEIRO, Rayan Fidel Martins; BASTOS, Gilmara de Nazareth Tavares; http://lattes.cnpq.br/2487879058181806
All the functions of the endocannabinoid system (ECS) are not yet fully understood, however this system is known to have a neuromodulatory effect, essentially attributed to cannabinoid type I receptors (CB1R), which systemic activation induces psychoactive effects. In contrast, the immunomodulatory effect of ECS, attributed mainly to cannabinoid type II receptors (CB2R), has been demonstrated as an alternative treatment for several acute or chronic inflammatory diseases, including neurodegenerative diseases in animal models via chronic CB2R activation. However, the effects of this treatment are still unclear shortly after its administration. In this sense, we seek to investigate the effects of the acute-systemic treatment of β-caryophyllene (BCP), a phyto-cannabinoid agonist of CB2R in a murine model of neuroinflammation induced by LPS. We performed the open field test (OF) 2 and 4 h after the induction of sickness behavior by Lipopolysaccharide (LPS) and demonstrated that in animals pretreated with BCP, in the 2 h window, there was maintenance in the quality of movement in animals that received LPS without alteration in the induction of sickness behavior, and increased activity in the aversive region of the apparatus in animals that did not receive LPS. Indicating the immune and neuromodulatory effect of BCP. We also performed the Morris Water Labyrinth (MWM) test 24 h after inoculation of LPS, however it was not possible to discriminate changes in learning, however the inoculated and untreated animals proved to be more likely to form spatial memory. Finally, we observed that pretreatment with BCP increases lipid peroxidation and nitrite concentration in the brain 2 h after LPS inoculation, thus suggesting an immediate increase in oxidative stress by acute treatment with BCP in neuroinflammatory models. Therefore, it is of fundamental importance to continue researching the immediate neurological and immunological effects of BCP treatment in healthy animal models and in neuroinflammatory models for better determination of the risks attributed to this treatment, as well as the addition of acute treatment to the detriment of the treatment. chronic in different neurological pathologies.